In the related art, as a cutting device for cutting a plate-shaped brittle material such as a glass plate or the like, a device including a laser radiation unit configured to radiate a laser beam to a workpiece such as a glass plate or the like to locally heat the workpiece, and a coolant injection unit configured to inject a coolant to the workpiece heated by the laser beam is disclosed (for example, see Patent Document 1).
In such a cutting device, when the coolant is injected to the workpiece, the coolant rebounds due to a force of injection and is scattered therearound. When the scattered coolant is scattered into a laser beam passage region through which the laser beam for heating the workpiece passes, the scattered coolant absorbs a part of the laser, and the workpiece cannot be sufficiently heated. With respect to such a problem, in Patent Document 1, as a shield plate is installed between a cooling area and a heating area, scattering of the coolant to the laser beam passage region is prevented.